I have not any noticable scratch on the boards after more than one year usage. And my kids really step on the boards. The boards have some sort of bulges made of rubber like material which I guess take the most wear.

We have the running boards and they were a little hard to adjust to, but once I got used to stepping out instead of down, I stopped having dirty pants. My son really uses them and they're great when I am washing or cleaning snow off the top of the car.